Urinary incontinence is a widespread problem in the United States and throughout the world. Urinary incontinence affects people of all ages and can severely impact a patient both physiologically and psychologically.
In approximately 30% of the women suffering from urinary incontinence, incontinence is caused by intrinsic sphincter deficiency (ISD), a condition in which the valves of the urethral sphincter do not properly coapt. In approximately another 30% of incontinent women, incontinence is caused by hypermobility, a condition in which the muscles around the bladder relax, causing the bladder neck and proximal urethra to rotate and descend in response to increases in intraabdominal pressure. Hypermobility may be the result of pregnancy or other conditions which weaken the muscles. In an additional group of women with urinary incontinence, the condition is caused by a combination of ISD and hypermobility.
In addition to the conditions described above, urinary incontinence has a number of other causes, including birth defects, disease, injury, aging, and urinary tract infection.
Numerous approaches for treating urinary incontinence are available. For example, several procedures for stabilizing and/or slightly compressing the urethra so as to prevent the leakage of urine have been developed. The stabilizing or compressive force may be applied directly by sutures passing through the soft tissue surrounding the urethra or, alternatively, may be applied by means of a sling located under the urethra and suspended by sutures. The sutures may be anchored to the pubic bone by means of bone anchors or, alternatively, the sutures may be attached to other structures such as fascia.
A device for dissecting around a tubular structure such as the urethra or the bladder neck is available from Lone Star Medical Products. The Lone Star device has two shafts which can be positioned in the tissue between the urethra and the vaginal wall using cystoscopy, vaginal or rectal examination, or an examination of the position of the instrument around the urethra with the bladder opened. The two shafts can be locked together to pinch the intervening tissue. A sharp blade is inserted into one of the shafts and advanced into the second shaft, cutting the tissue in between the two shafts. The cut in the tissue can be expanded using a right angle clamp and an artificial sphincter guided by a suture attached to the cutting blade of the device can be introduced into the expanded cut.
With the Lone Star device, the distance between the two shafts cannot be gradually adjusted. In addition, the ends of the shafts of the Lone Star device come in direct contact with the tissue or bone while being advanced towards the tissue between the urethra and the upper vaginal wall. The shafts of the Lone Star device are flat at their distal ends.
Thus, there is a need for devices which simplify treatments for urinary incontinence and increase their safety. Sling application devices for treating urinary incontinence which reduce the risk of inadvertent pinching of the urethra and undesirable scoring of tissue or bone during advancement of the device would be particularly desirable. It is also desirable to have a sling application device that does not employ a guiding suture and can create or maintain an opening in the tissue between the urethra and the upper vaginal wall without the use of a right angle clamp, thereby simplifying the procedure.
U.S. Pat. No. 5,611,515, issued Mar. 18, 1997 to Benderev et al., introduces pioneering minimally invasive percutaneous and transvaginal bladder neck stabilization approaches. The percutaneous approach of Benderev et al. involves stabilizing the bladder neck using a bone anchor which is percutaneously introduced from the abdominal side of the patient. The transvaginal approach of Benderev et al. involves stabilizing the bladder neck using a staple or bone anchor which is transvaginally placed into the pubic bone. There is also a need for further devices and methods for improving or maintaining urinary continence involving stabilization or compression of the bladder neck or urethra, particularly devices and methods of the present invention that are less invasive than many of those currently available.